In general, when using rigid spacers, the spacer must be cut into precise lengths and the corners then joined by welding or the like. When using flexible spacers, if the degree of flexibility is sufficient to permit a spacer to be bent around a corner, the only problem then arising is the "bunching" of the material at the corner which can affect the performance of the spacer in an assembled IG unit.
Numerous strip applying tools have been proposed in the art, however, these tools have limitations in that many of them incorporate many moving parts, which are susceptible to mechanical failure. In addition, during an application procedure of strip material to a substrate and more particularly, when a corner needs to be formed in the strip, the application procedure using generally known tools must be interrupted and the corner formed therein. As such, this not only has a negative impact on productivity, but additionally provides a potential "weak spot" in terms of the insulation capacity of the strip.
In my earlier patents noted above, one solution was to punch out a portion of the flexible spacer internally of the spacer body so that a physical portion of the material was removed. Thus the spacer was able to form a tight 90.degree. corner. However, by physically removing a portion of the material on the internal face of the spacer strip, the integrity of the strip can be destroyed relative to vapour transmission. Spacers in use today include a desiccant strip or layer on the internal face and by removing a portion of the body at its internal face, the continuity of the desiccant layer is interrupted at several places throughout the IG assembly, which is undesirable.